Parenteral delivery of liquid medicaments into dermal tissue of a patient may be accomplished by administering bolus injections using a needle and a reservoir, or continuously by appropriate dispensers or transdermal patch technology which may be driven by gravity. Gravity feed systems compromise the patient's mobility and lifestyle and limit the therapy to simplistic flow rates and profiles. Ambulatory infusion pumps have been developed that provide sophisticated fluid delivery profiles accomplishing bolus requirements, continuous infusion and variable flow rate delivery.
Ambulatory pump systems typically include a reservoir containing the liquid medicament and make further use of an injection assembly comprising an injection needle and some kind of tube structure through which the medicament is transported by way of a feeder of the infusion pump.
Document WO 2013/041702 A1 discloses a peristaltic pump comprising a tube for transporting the liquid medicament, wherein the tube is arranged along a longitudinal axis. The peristaltic pump further comprises a rotatable pump head for causing a squeezing of the tube, wherein the pump head is rotatable about a rotation axis. The peristaltic pump further comprises a receptacle that is configured to receive a cartridge or a container holding the material to be transported. With peristaltic pumps featuring a pump head or feeder a rather hermetically sealed fluid path from the cartridge towards an injection needle can be provided such that the pump head or any other fluid feeding component of the peristaltic pump does not get in direct contact with the medicament. In this way, contamination of the medicament by components of the pump as well as contamination of the pump by the medicament can be effectively avoided. For reasons of hygiene as well as for patient safety and patient compliance it is of particular benefit to make use of disposable reservoirs or cartridges containing the medicament as well as to make use of disposable fluid transferring components that have to be replaced from time to time.
A fluid transferring component of such drug delivery systems providing a fluid path from a medicament reservoir towards an injection needle may be denoted as injector in the present context. For hygienic reasons as well as for patient safety and compliance it is desirable to provide a rather easy and intuitive replacement of cartridge and injector. It is a further aspect to provide a well-defined and smoothly operating fluid transferring mutual coupling of a disposable cartridge and a disposable injector. It would be rather beneficial to establish a fluid transferring coupling between injector and cartridge just immediately before the drug delivery device is initially operated so that a sealed cartridge is not prematurely or unnecessarily coupled with the injector. In this context it would be of further benefit to avoid that liquid medicament already enters the injector and its fluid transferring system, e.g. a fluid transferring tube prior to a delivery operation to be conducted by the drug delivery device.